The invention concerns a crank drive for controlling the sliding movement and the tilting movement of the cover of sliding-lifting roofs of motor vehicles of the type having an internally toothed crank that coacts with stop means at positions corresponding to fully pushed-back, fully tilted-out and closed positions of the cover.
In the case of a known crank drive of this type (DE-AS No. 23 33 666, corresponding to U.S. Pat. No. 3,948,119), the crank is disposed below a rosette-shaped body forming a crank support, in which a toothed ring and an eccentric (which are rotationally fixed relative to the crank) are housed, the toothed ring and eccentric being, themselves, disposed on a shaft connected with the crank and projecting from said crank. A significant disadvantage of the known crank drive is that it requires a relatively extensive installation space in the vertical direction. However, a requirement for additional space in a vertical direction is especially undesirable because of the fact that a lowering of the C.sub.d value and a resulting flat construction are desired in modern motor vehicles.
The invention is, therefore, based on the task of creating a crank drive of the above-mentioned type that can be installed in a flat manner.
According to the invention, this problem is solved in a simple and excellent manner by means of the fact that the crank chamber concentrically encloses the support (which is developed as a bearing body) and houses the toothed ring and the eccentric, as well as the stop means. The construction according to the invention permits an extremely flat design of the crank drive. Therefore, only a minimum of vertical installation space is required for the crank drive. In addition, an especially compact and convenient shape of the drive is obtained. This drive can, therefore, be housed in an inconspicuous manner. Its assembly is very simple.
Advantageously, the support can be essentially ring-shaped and can be housed in a ring duct of the crank chamber. In this case, the crank chamber may advantageously be rotatably supported on the outside surface of the support as well as by means of a central pivot pin at the, for this purpose, concentric inside surface of the ring borehole. In this manner, a sturdy mounting of the crank is ensured even in the case of an extremely flat construction.
In order to keep the number of the individual components of the crank drive small, the eccentric is preferably rigidly connected with the pivot pin of the crank chamber. In particular, it may be disposed at the bottom of the ring duct.
In a further development of the invention, the toothed ring is connected with a control disk while being fixed in regard to rotation, with the first stop means that interact with the counter-stop means of the support being mounted on said control disk. In this case, the first stop means are preferably formed by a nose of the control disk that projects in an axial direction, said nose engaging in an annular groove of the support forming said counter-stop means and extending over an angle of less than 360.degree.. In this manner, the number of crank turns required to bring the cover into the fully pushed-back or fully tilted position may simply and effectively be limited.
The toothed ring and the control disk may be connected rotationally by means of a carrier, and the control disk may be rotatably disposed around the center of rotation of the crank. However, in principle, it is also possible to combine the toothed ring and the control disk into one single component carrying out a circulating eccentric movement with respect to the internal toothing of the support.
When the toothed ring and the control disk are separate, the control disk is preferably disposed, in an axial direction, resting against the toothed ring on the central pivot pin of the crank chamber. Thus, while, in this case, the toothed ring carries out a circulating eccentric movement, the control disk is, by means of the carrier, caused to carry out a synchronous rotating movement.
A recess in the crank chamber may be provided as the counter-stop means for the second stop means, and the control disk may, in this case, have a control duct shaped in such a way that it only releases the second stop means in the crank position corresponding to the closing position of the cover, for an engagement with the recess of the crank chamber. In this case, the second stop means may, in an especially simple manner, be formed by a stop pin that is disposed in the crank chamber so that it can be radially adjusted, with said stop pin being prestressed to the outside in a springy manner and being provided with a nose engaging into the control duct in order to hold the stop pin against the force of the spring in a position that is radially retracted toward the inside. The control duct has a radial widening that releases the stop pin for engagement in the recess of the crank chamber. In this manner, the crank is reliably and precisely locked in the position that corresponds to the closing position of the cover.
For the optional release of the locking of the crank, a slide is preferably provided which can be operated from the outside of the crank chamber and adjusted in a radial direction, and which is radially prestressed to the outside in a springy manner, by means of which the stop pin can be disengaged from the recess of the crank chamber.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a single embodiment in accordance with the present invention.